(1) Field of the Invention
The present invention relates to marine vessels and more particularly to wire-guided torpedoes for use thereon.
(2) Brief Description of the Prior Art
The MK 48 Torpedo utilizes a torpedo Tail Mounted Dispenser (TMD) as an integral part of its guidance wire communication system. The function of the TMD is to house a guidance wire coil and allow for successful deployment of a hollow core flexible cable known as a flex-hose that is used to position the guidance wire that is paying out through it, below the submarine's keel and propeller. A prior art TMD is disclosed in U.S. Pat. No. 5,385,109, the contents of which are incorporated herein by reference.
The TMD is attached to the tail end of the torpedo prior to loading the torpedo onboard the submarine and is stowed along with the torpedo inside of the submarine's torpedo room. Torpedoes are presently secured on U.S. Naval submarine weapon stowage and handling system (WSHS) by means of four dollies equipped with lashing straps. The TMD is suspended off the tail end of the torpedo and is not secured by one of the dollies and lashing straps. It has been determined that certain shock and vibration levels can cause significant displacement of the TMD, which can damage the TMD and the torpedo.
The prior art discloses a number of devices for the wire guidance of torpedoes and for reducing shock and vibration.
U.S. Pat. No. 3,565,028 to Hancks et al., for example, discloses a torpedo, which can be launched conventionally from a torpedo tube and trails a hydrophone on a long cable. A shroud encircling the propellers is articulated on a ball and socket joint to steer the torpedo, and to serve as a reel for carrying the long cable until after launching. Holddown fingers, which keep the coiled cable in place, are scuttled a measured time after launch. There is, however no disclosure of any means for reducing shock and vibration.
U.S. Pat. No. 4,819,503 to Fazi, Jr. et al. discloses a low frequency structure borne vibration isolation mount including an annular disk pad of vibration damping material which is sandwiched and bonded between two similar light but rugged annular disks. The annular disk pad and the two annular disks have equal numbers of matching and corresponding holes along the circumferences thereof. The sizes of the holes are so chosen that one of the annular disks can be secured to the moving piece of equipment and isolated from everything else and the other annular disk can be secured to the stationary piece of equipment. The vibrations of the moving piece of equipment are thus isolated from everything else. There is, however, no teaching of any way of increasing survivability during or after shock events.
U.S. Pat. No. 4,887,788 to Fisher et al. discloses a device for absorbing the energy of vibration of one of two abutting members which has begun to vibrate due to forces applied to either of the two abutting members, so as to reduce the frequency and magnitude of vibration of one of the two abutting members. The primary energy absorbing element is a piece of elastomeric resilient material which contains a core (or cores) of a substantially incompressible, highly efficient dampening material; the presence or absence of this core of highly efficient dampening material will depend upon desired device stiffness and dampening characteristics. The primary energy-absorbing element is surrounded by a flexible reinforced shell, which contains and restrains said element, yet allows said element to deform in the transverse and vertical directions. Two end pieces or mounting plates are secured to opposite ends of the primary energy-absorbing element. This patent, however, does not disclose a method of protecting a structure against high impact shock events.
U.S. Pat. No. 5,040,764 to Dubois discloses a mounting assembly for absorbing low frequency vibrational energy as produced by a source and isolating a base member therefrom, the mounting assembly including a central metallic ring, non-metallic foam rings located on both sides of the central metallic ring in concentric relation with respect thereto, and inner and outer metallic ring members engaging said foam rings in concentric relation, the foam rings defining a spongy mass that effectively absorbs the low frequency vibrational energy emanating from the source. This patent does not disclose any shock benefits to the torpedo or the torpedo mounted dispenser. In addition, the design disclosed in this patent requires mounting to multiple structures.
U.S. Pat. No. 5,158,030 to DuBois et al. discloses a damped flexible seal assembly for a torpedo, which isolates the tailcone thereof from vibrational energy present in the drive shaft assembly. A pair of outside flanges, each of which include an inwardly facing groove and an O-ring constrained therein, provide a watertight seal against the outer non-rotating surface of the drive shaft assembly. An inside flange includes an outwardly facing groove and an O-ring constrained therein, and provides a watertight seal against the inner surface of the tail cone. Two cast-in-place elastomeric seals provide a watertight seal between the flanges and further provide a damping barrier between the outside flanges and the inside flanges for damping vibrational energy present in the drive shaft assembly before the energy can reach the tailcone through the seal assembly. This arrangement does not, however, provide any benefits toward enhancing the chances that a torpedo will survive a shock event.
U.S. Pat. No. 5,396,855 to DuBois discloses an underwater vehicle tailcone assembly including a forward flange, a first tubular sheath extending rearwardly from the forward flange, and elastomer material bonded to inner and outer surfaces of the first sheath to form a forward chamber wall. The assembly further includes an aft flange, a second tubular sheath extending forwardly from the aft flange, and elastomer material bonded to inner and outer surfaces of the second sheath to form an aft chamber wall. The assembly still further includes a rigid housing wall disposed between a rearward end of the forward chamber wall and a forward end of the aft chamber wall. The forward chamber wall forms a continuous tailcone wall from a forward edge of the forward flange to a rearward edge of the aft flange. This patent, however, also does not disclose any features for protecting the torpedo from damage during shock events.